1/5 scale Gee Bee Model D (From foam to balsa)

[cyclone3350]

Moving away from electrics for a while. My next big project is probably too big a step without an intermediate step in between, So, I've decided to try this one first & hopefully will be quick & not too painful of a learning curve. I made the original one out of 2mm depron using this website: https://www.rcgroups.com/forums/showthread.php?290818-Electric-Orange-Gee-Bee-D-Park-Racer The original version is 36" & I made this 1s'er reduced to 20". The plan is to use ply and balsa for the fuse, balsa sheet a hot wire pink foam wing & I will figure out what to do for the tailfeathers later. I have this Magnum XL 91FSR that desperately needs a home. I will use a Morris Mini Motors CDI conversion & see if it will run on gas. If not, the CDI will do well for nitro. Shrunk the plans down to 50% too make it into individual pages and then scanned them and reprinted them @ Kinko's @ 340%. Now it is off to the jig and band saw.

 

[OliverW]

I'm in the same boat. Been much preferring the simplicity of my fuel powered birds lately

 

[cyclone3350]

I'm in the same boat. Been much preferring the simplicity of my fuel powered birds lately

I am finding that once U get up to certain size, the weight and space of the batts start to become an issue. Plus, when doing a large Golden Age, U gotta have the noise of a 4 stroker.

 

[OliverW]

Yeah true. I've been looking at doing a golden age build for a long time, just have had no time for building lately. If I were to though I'd get a big ol gee bee z and buy a moki radial for it lol. But yeah I see what you're saying. Did a big electric setup and wasn't a huge fan. Even for small stuff I've been preferring glow. Just fuel up, tap the spinner with the starter, and it fires right up!

 

[cyclone3350]

Yeah true. I've been looking at doing a golden age build for a long time, just have had no time for building lately. If I were to though I'd get a big ol gee bee z and buy a moki radial for it lol. But yeah I see what you're saying. Did a big electric setup and wasn't a huge fan. Even for small stuff I've been preferring glow. Just fuel up, tap the spinner with the starter, and it fires right up!

That's funny U mentioned it. My dream bird is a Moki 7 banger on a 1/3rd Pup.

 

[OliverW]

That's funny U mentioned it. My dream bird is a Moki 7 banger on a 1/3rd Pup.

That'd be an awesome ship. A guy in my club has a 1/3 pup with a big quadra on the nose. Sounds really cool with the muffler he's using

 

[Baron VonHelton]

Can foam even support one of those heavy metal (PUN!) gas motors?

 

[OliverW]

Yep. Easily if the plane has some mild balsa reinforcements, along with some ply around the firewall area. Me and @BlockerAviation have both done it with his attempts being more successful as mine was a nutball 😂

 

[cyclone3350]

Yep. Easily if the plane has some mild balsa reinforcements, along with some ply around the firewall area. Me and @BlockerAviation have both done it with his attempts being more successful as mine was a nutball 😂

Looking @ your stuff & seeing what an amazing job @BlockerAviation did with his Cub, is what gave me the idea. For this size, my fuse is going to be all ply formers and balsa sheeting.

 

[BlockerAviation]

Looking @ your stuff & seeing what an amazing job @BlockerAviation did with his Cub, is what gave me the idea. For this size, my fuse is going to be all ply formers and balsa sheeting.

Thanks man, that means a lot to here that. I have a feeling that the geebee will be awesome in the air and a really good conversation piece. At least my cub is, you should see the look I get when I say it's foam board 😂

 

[cyclone3350]

OMG! 3 days of work and pieces of carboard is all I have to show!

This is after doing some measurements & realizing that the original plans were too narrow. Also, the weight of a fully sheeted balsa fuse and solid balsa tail for the wing area was also an issue. I finally settled down on the original plan, widened for the front of the fuse, sheeted, and the rear built up portion of a Haffke set of plans. The tail will also be built out of 3/16 balsa sticks. After days of plotting points of contact and drawing things out on the drafting board, I finally came up with some parts patterns. Did some dry fitting to see how everything lines up before I star cutting. I still have the cockpit hatch to go and some 1/16 birch ply doublers to go behind the 1/4 ply firewall. The rest of the formers and servo / receiver tray will be 1/8th lite ply, & the last 2 formers will be 1/8th balsa. I am still sticking to a foam core set of wings. God, I hope to have this fuse framed up by tonight. BTW, to make this 1/5, the WS will be 60" & the length is 41.5"

 

[cyclone3350]

I had to be out of town for the past week. Now that I am back, I definitely put the scroll saw to good use. All the cardboard patterns R now plywood and put together. Got the rear section framed up & ready to join the front section. If U take clothes pins & turn them inside out, they make for good mini clamps.

 

[cyclone3350]

Finished framing up the the rear fuse section. I did this part in 2 halves & glued them together. The pans had only 2 former for this. I thought this to be insufficient, but figured that if that if this is deigned this way, then it should work. Maybe, if covering with something low shrink like silkspan. I plan on using one of my last rolls of Solatex & that stuff would shrink hour glass shapes into the fuse for sure. So how do I add extra formers into something already frame up? Building rectangles with balsa strips & adding cross stringers to attach to the side stringers. Once glued, sawed out the center sections & it worked. Took some time unfortunately. Going back at it tonight. I think I will hot wire the wings. Hmmm, maybe too tired for that & should just do the tail feathers.

 

[FlyingTyger]

If you don't already plan to, I would add a ply gusset at the rear of the wing saddle. Otherwise I see that as a weak point that may cause problems over time.

 

[cyclone3350]

If you don't already plan to, I would add a ply gusset at the rear of the wing saddle. Otherwise I see that as a weak point that may cause problems over time.
View attachment 215833

That section is going to be a 1/8th balsa doubler followed by 1/16th balsa sheeting. I am waiting for the wing to be done so I can make an exact cut out for the saddle.This is the mock up with the sheeting pattern made. A 1/8th lite ply gusset behind the doubler would be an added strength without adding much to the weight.

 

[Flightspeed]

ok, I saw four strokes mentioned. How do y’all start them things! My starter won’t touch em! Chicken stick don’t really work for first time starting a engine. I’ll stick with two stroke as much as possible. Thanks to miserable 4 stroke I have a plane I can’t fly lol.

 

[FlyingTyger]

ok, I saw four strokes mentioned. How do y’all start them things! My starter won’t touch em! Chicken stick don’t really work for first time starting a engine. I’ll stick with two stroke as much as possible. Thanks to miserable 4 stroke I have a plane I can’t fly lol.

What size?

 

[FlyingTyger]

That section is going to be a 1/8th balsa doubler followed by 1/16th balsa sheeting. I am waiting for the wing to be done so I can make an exact cut out for the saddle.This is the mock up with the sheeting pattern made. A 1/8th lite ply gusset behind the doubler would be an added strength without adding much to the weight.

Perfect. For some reason I thought you were using foamboard for the forward solid area.

 

[cyclone3350]

ok, I saw four strokes mentioned. How do y’all start them things! My starter won’t touch em! Chicken stick don’t really work for first time starting a engine. I’ll stick with two stroke as much as possible. Thanks to miserable 4 stroke I have a plane I can’t fly lol.

I am about to find out. This one was given to me, so I used that rational to justify the additional expense & ordered an RCEXL ignition system for it. Hope it works.

 

[cyclone3350]

What size?

Magnum XL 91 FSR.